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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2009-2011  Mario de Sousa (msousa@fe.up.pt)

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 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

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 *

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 *  This program is free software: you can redistribute it and/or modify

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 *  it under the terms of the GNU General Public License as published by

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 *  the Free Software Foundation, either version 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

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/*

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 * This is the main stage 3a file.

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 *

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 * In stage 3a some helpful symbol tables are instanciated and populated.

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 * These symbol tables wll then be used by stage3b and atage4 code generators.

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 */

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// #include <stdio.h>  /* required for NULL */

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#include <string>

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#include <iostream>

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#include <sstream>

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#include <typeinfo>

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#include <list>

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#include <strings.h>

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#include "../util/symtable.hh"

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#include "../util/dsymtable.hh"

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#include "../absyntax/visitor.hh"

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//#define DEBUG

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#ifdef DEBUG

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#define TRACE(classname) printf("\n____%s____\n",classname);

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#else

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#define TRACE(classname)

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#endif

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#define ERROR error_exit(__FILE__,__LINE__)

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/* function defined in main.cc */

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extern void error_exit(const char *file_name, int line_no);

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/***********************************************************************/

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/***********************************************************************/

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/***********************************************************************/

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/***********************************************************************/

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/* returns 0 if the names are equal!! */

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/* NOTE: it must ignore case!! */

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int compare_identifiers(symbol_c *ident1, symbol_c *ident2) {

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  token_c *name1 = dynamic_cast<token_c *>(ident1);

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  token_c *name2 = dynamic_cast<token_c *>(ident2);

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  if ((name1 == NULL) || (name2 == NULL))

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    /* invalid identifiers... */

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    return -1;

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  if (strcasecmp(name1->value, name2->value) == 0)

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    return 0;

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  /* identifiers do not match! */

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  return 1;

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}

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/***********************************************************************/

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/***********************************************************************/

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/***********************************************************************/

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/***********************************************************************/

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/* A symbol table with all globally declared functions... */

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function_declaration_c null_symbol1(NULL,NULL,NULL,NULL);

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dsymtable_c<function_declaration_c *, &null_symbol1> function_symtable;

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/* A symbol table with all globally declared functions block types... */

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function_block_declaration_c null_symbol2(NULL,NULL,NULL);

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symtable_c<function_block_declaration_c *, &null_symbol2> function_block_type_symtable;

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/* A symbol table with all globally declared program types... */

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program_declaration_c null_symbol3(NULL,NULL,NULL);

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symtable_c<program_declaration_c *, &null_symbol3> program_type_symtable;

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/* A symbol table with all user declared type definitions... */

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/* Note that function block types and program types have their

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 * own symbol tables, so do not get placed in this symbol table!

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 *

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 * The symbol_c * associated to the value will point to the data type declaration.

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 */

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symbol_c null_symbol4;

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symtable_c<symbol_c *, &null_symbol4> type_symtable;

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/* A symbol table with all values declared for enumerated type... */

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/* Notes:

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 * - if the value is defined multiple times the value

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 * is the null pointer.

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 *

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 * - The stored symbol_c * associated to the value points to the enumerated_type_name

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 * (i.e. the name of the enumerated data type) in which the the value/identifier

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 * is used/declared.

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 *

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 * - We could re-use the null_symbol4 object, but it is safer to use a distinct object

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 *   (i.e. it might make it easier to find strange bugs).

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 */

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symbol_c null_symbol5;

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symtable_c<symbol_c *, &null_symbol5> enumerated_value_symtable;

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/***********************************************************************/

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/***********************************************************************/

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/***********************************************************************/

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/***********************************************************************/

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class populate_symtables_c: public iterator_visitor_c {

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  private:

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	symbol_c *current_enumerated_type;

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  public:

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    populate_symtables_c(void) {

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    	current_enumerated_type = NULL;

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    };

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    virtual ~populate_symtables_c(void) {}

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  public:

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  /*************************/

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  /* B.1 - Common elements */

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  /*************************/

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  /*******************************************/

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  /* B 1.1 - Letters, digits and identifiers */

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  /*******************************************/

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  /*********************/

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  /* B 1.2 - Constants */

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  /*********************/

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  /******************************/

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  /* B 1.2.1 - Numeric Literals */

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  /******************************/

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  /*******************************/

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  /* B.1.2.2   Character Strings */

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  /*******************************/

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  /***************************/

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  /* B 1.2.3 - Time Literals */

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  /***************************/

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  /************************/

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  /* B 1.2.3.1 - Duration */

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  /************************/

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  /************************************/

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  /* B 1.2.3.2 - Time of day and Date */

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  /************************************/

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  /**********************/

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  /* B.1.3 - Data types */

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  /**********************/

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  /***********************************/

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  /* B 1.3.1 - Elementary Data Types */

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  /***********************************/

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  /********************************/

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  /* B.1.3.2 - Generic data types */

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  /********************************/

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  /********************************/

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  /* B 1.3.3 - Derived data types */

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  /********************************/

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  /*  subrange_type_name ':' subrange_spec_init */

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  void *visit(subrange_type_declaration_c *symbol) {

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    TRACE("subrange_type_declaration_c");  

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    type_symtable.insert(symbol->subrange_type_name, symbol->subrange_spec_init);

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    return NULL;

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  }

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  /*  enumerated_type_name ':' enumerated_spec_init */

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  void *visit(enumerated_type_declaration_c *symbol) {

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    TRACE("enumerated_type_declaration_c");

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    type_symtable.insert(symbol->enumerated_type_name, symbol->enumerated_spec_init);

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    current_enumerated_type = symbol->enumerated_type_name;

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    symbol->enumerated_spec_init->accept(*this);

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    current_enumerated_type = NULL;

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    return NULL;

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  }

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  /* enumerated_specification ASSIGN enumerated_value */

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  void *visit(enumerated_spec_init_c *symbol) {

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    return symbol->enumerated_specification->accept(*this);

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  }

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  /* [enumerated_type_name '#'] identifier */

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  void *visit(enumerated_value_c *symbol) {

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    if (current_enumerated_type != NULL) {

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      if (symbol->type != NULL) ERROR;

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      symbol_c *value_type = enumerated_value_symtable.find_value(symbol->value);

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      /* NOTE: The following condition checks whether the same identifier is used more than once

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       *       when defining the enumerated values of the type declaration of the new enumerated type.

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       *       If this occurs, then the program beeing compiled contains a semantic error, which

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       *       must be caught and reported by the semantic analyser. However, since

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       *       this code is run before the semantic analyser, we must not yet raise the ERROR (internal

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       *       compiler error message).

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       *       For this reason, the follosing check is commented out.

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       */

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      /* if (value_type == current_enumerated_type) ERROR; */

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      if (value_type == enumerated_value_symtable.end_value())

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	/* This identifier has not yet been used in any previous declaration of an enumeration data type.

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	 * so we add it to the symbol table.

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	 */

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        enumerated_value_symtable.insert(symbol->value, current_enumerated_type);

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      else if (value_type != NULL)

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	/* This identifier has already been used in a previous declaration of an enumeration data type.

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	 * so we set the symbol in symbol table pointing to NULL.

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	 */

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        enumerated_value_symtable.set(symbol->value, NULL);

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    }

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    return NULL;

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  }

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  /*  identifier ':' array_spec_init */

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  void *visit(array_type_declaration_c *symbol) {

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    TRACE("array_type_declaration_c");

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    type_symtable.insert(symbol->identifier, symbol->array_spec_init);

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    return NULL;

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  }

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  /*  simple_type_name ':' simple_spec_init */

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  void *visit(simple_type_declaration_c *symbol) {

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    TRACE("simple_type_declaration_c");

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    type_symtable.insert(symbol->simple_type_name, symbol->simple_spec_init);

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    return NULL;

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  }

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  /*  structure_type_name ':' structure_specification */

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  void *visit(structure_type_declaration_c *symbol) {

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    TRACE("structure_type_declaration_c");

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    type_symtable.insert(symbol->structure_type_name, symbol->structure_specification);

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    return NULL;

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  }

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  /*********************/

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  /* B 1.4 - Variables */

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  /*********************/

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  /********************************************/

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  /* B.1.4.1   Directly Represented Variables */

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  /********************************************/

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  /*************************************/

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  /* B.1.4.2   Multi-element Variables */

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  /*************************************/

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  /******************************************/

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  /* B 1.4.3 - Declaration & Initialisation */

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  /******************************************/

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  /**************************************/

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  /* B.1.5 - Program organization units */

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  /**************************************/

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  /***********************/

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  /* B 1.5.1 - Functions */

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  /***********************/

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  public:

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  /*   FUNCTION derived_function_name ':' elementary_type_name io_OR_function_var_declarations_list function_body END_FUNCTION */

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  /* | FUNCTION derived_function_name ':' derived_type_name io_OR_function_var_declarations_list function_body END_FUNCTION */

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  void *visit(function_declaration_c *symbol) {

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    TRACE("function_declaration_c");

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    function_symtable.insert(symbol->derived_function_name, symbol);

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    /* symbol->derived_function_name->accept(*this);  */ /* Function name */

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    /* symbol->type_name->accept(*this);              */ /* return data type */

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    /* symbol->var_declarations_list->accept(*this);  */ /* Function parameters and variables */

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    /* symbol->function_body->accept(*this);          */ /* Function body */

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    return NULL;

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  }

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  /*****************************/

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  /* B 1.5.2 - Function Blocks */

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  /*****************************/

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  public:

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  /*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

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  //SYM_REF4(function_block_declaration_c, fblock_name, var_declarations, fblock_body, unused)

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  void *visit(function_block_declaration_c *symbol) {

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    TRACE("function_block_declaration_c");

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    function_block_type_symtable.insert(symbol->fblock_name, symbol);

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  /*

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    symbol->fblock_name->accept(*this);

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    symbol->var_declarations->accept(*this);

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    symbol->fblock_body->accept(*this);

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  */

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    return NULL;

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  }

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  /**********************/

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  /* B 1.5.3 - Programs */

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  /**********************/

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  public:

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  /*  PROGRAM program_type_name program_var_declarations_list function_block_body END_PROGRAM */

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  //SYM_REF4(program_declaration_c, program_type_name, var_declarations, function_block_body, unused)

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  void *visit(program_declaration_c *symbol) {

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    TRACE("program_declaration_c");

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    program_type_symtable.insert(symbol->program_type_name, symbol);

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  /*

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    symbol->program_type_name->accept(*this);

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    symbol->var_declarations->accept(*this);

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    symbol->function_block_body->accept(*this);

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  */

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    return NULL;

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  }

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}; /* populate_symtables_c */

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void absyntax_utils_init(symbol_c *tree_root) {

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  populate_symtables_c populate_symbols;

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  tree_root->accept(populate_symbols);

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}

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